The ADM8611/ADM8616/ADM8617/ADM8618 are supervisory circuits which monitor power supply voltage levels and code execution integrity in microprocessor-based systems. A power-on-reset signal is generated when the supply voltage rises to a preset threshold level. The ADM8611's debounced manual reset input can be used to initiate a reset by means of an external push-button or logic signal. The ADM8616ADM8618 have an on-chip watchdog timer which can reset the microprocessor if it fails to strobe within a preset timeout period.